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| author | H. Peter Anvin <hpa@zytor.com> | 2008-02-25 15:44:24 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2008-02-25 15:44:24 -0800 |
| commit | 6d154a74c21df32fcc3b2fbef11039f2487dca75 (patch) | |
| tree | 8bc05100aa05b18db5a3fcb36b879c7cd8738ef7 | |
| parent | eaaf9a75bb6767b00db51518dffadd714199741d (diff) | |
| download | syslinux-6d154a74c21df32fcc3b2fbef11039f2487dca75.tar.gz | |
gptmbr: save phdr -> bootsect on the stack, saving one byte
| -rw-r--r-- | mbr/gptmbr.S | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mbr/gptmbr.S b/mbr/gptmbr.S index 10dfd45a..4009643f 100644 --- a/mbr/gptmbr.S +++ b/mbr/gptmbr.S @@ -115,6 +115,7 @@ next: xorl %edx,%edx incw %ax movw $phdr, %bx + pushw %bx /* -8(%bp) phdr == bootsect */ call read_sector /* Number of partition sectors */ @@ -189,12 +190,13 @@ found_part: /* * boot: invoke the actual bootstrap. %ds:%si points to the - * partition information in memory. + * partition information in memory. The top word on the stack + * is phdr == 0x7c00 == the address of the boot sector. */ boot: movl (32+16)(%si),%eax movl (36+16)(%si),%edx - movw $bootsec,%bx + popw %bx call read_sector cmpw $0xaa55, -2(%bx) jne missing_os /* Not a valid boot sector */ |